Nonideal transport of reactive solutes in heterogeneous porous media 6. Microscopic and macroscopic approaches for incorporating heterogeneous rate-limited mass transfer

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Two major approaches have been used to incorporate heterogeneous ratelimited mass transfer into mathematical models for solute transport. One focuses on processes operative at the microscopic scale and associated grain-scale heterogeneity, while the other stresses the macroscopic variability of the medium and the field-scale behavior of solute transport. In this paper, we examine the conceptual framework and model formulation of these two approaches in an attempt to evaluate potential commonality. Numerical solvers are developed for both sets of governing equations, and the performance of these two models is tested for two systems, each incorporating one of two types of mass transfer mechanisms. The results show that despite differences in conceptualization and formulation, the models produce comparable behavior for smallerscale systems. However, greater deviations are observed at larger scales. This suggests that caution should be exercised when using mathematical modeling for elucidating the specific processes that may be influencing reactive-solute transport for a given system. We also evaluate the impact of microscopic-scale mass transfer heterogeneity on field-scale transport in systems for which hydraulic conductivity is spatially variable. The results show that inclusion of locally heterogeneous mass transfer does not appear to significantly influence the mean transport behavior for systems with field-scale heterogeneity. However, it does appear to influence low-concentration tailing. For simulations of reactive transport over extended distances, models with locally heterogeneous mass transfer may 'preserve' the nonequilibrium effects associated with rate-limited mass transfer better than models incorporating locally uniform mass transfer when both pore-scale and field-scale heterogeneity coexist.

Original languageEnglish (US)
Pages (from-to)2853-2867
Number of pages15
JournalWater Resources Research
Volume36
Issue number10
StatePublished - 2000

Fingerprint

porous media
mass transfer
solutes
Porous materials
porous medium
solute
Mass transfer
Solute transport
soil transport processes
solute transport
mathematical models
reactive transport
Hydraulic conductivity
Tailings
rate
conceptual framework
hydraulic conductivity
tailings
preserves
Mathematical models

ASJC Scopus subject areas

  • Environmental Science(all)
  • Environmental Chemistry
  • Aquatic Science
  • Water Science and Technology

Cite this

@article{24f6f20b477a4f42b73fc874cd00e47b,
title = "Nonideal transport of reactive solutes in heterogeneous porous media 6. Microscopic and macroscopic approaches for incorporating heterogeneous rate-limited mass transfer",
abstract = "Two major approaches have been used to incorporate heterogeneous ratelimited mass transfer into mathematical models for solute transport. One focuses on processes operative at the microscopic scale and associated grain-scale heterogeneity, while the other stresses the macroscopic variability of the medium and the field-scale behavior of solute transport. In this paper, we examine the conceptual framework and model formulation of these two approaches in an attempt to evaluate potential commonality. Numerical solvers are developed for both sets of governing equations, and the performance of these two models is tested for two systems, each incorporating one of two types of mass transfer mechanisms. The results show that despite differences in conceptualization and formulation, the models produce comparable behavior for smallerscale systems. However, greater deviations are observed at larger scales. This suggests that caution should be exercised when using mathematical modeling for elucidating the specific processes that may be influencing reactive-solute transport for a given system. We also evaluate the impact of microscopic-scale mass transfer heterogeneity on field-scale transport in systems for which hydraulic conductivity is spatially variable. The results show that inclusion of locally heterogeneous mass transfer does not appear to significantly influence the mean transport behavior for systems with field-scale heterogeneity. However, it does appear to influence low-concentration tailing. For simulations of reactive transport over extended distances, models with locally heterogeneous mass transfer may 'preserve' the nonequilibrium effects associated with rate-limited mass transfer better than models incorporating locally uniform mass transfer when both pore-scale and field-scale heterogeneity coexist.",
author = "Zhen Li and Brusseau, {Mark L}",
year = "2000",
language = "English (US)",
volume = "36",
pages = "2853--2867",
journal = "Water Resources Research",
issn = "0043-1397",
publisher = "American Geophysical Union",
number = "10",

}

TY - JOUR

T1 - Nonideal transport of reactive solutes in heterogeneous porous media 6. Microscopic and macroscopic approaches for incorporating heterogeneous rate-limited mass transfer

AU - Li, Zhen

AU - Brusseau, Mark L

PY - 2000

Y1 - 2000

N2 - Two major approaches have been used to incorporate heterogeneous ratelimited mass transfer into mathematical models for solute transport. One focuses on processes operative at the microscopic scale and associated grain-scale heterogeneity, while the other stresses the macroscopic variability of the medium and the field-scale behavior of solute transport. In this paper, we examine the conceptual framework and model formulation of these two approaches in an attempt to evaluate potential commonality. Numerical solvers are developed for both sets of governing equations, and the performance of these two models is tested for two systems, each incorporating one of two types of mass transfer mechanisms. The results show that despite differences in conceptualization and formulation, the models produce comparable behavior for smallerscale systems. However, greater deviations are observed at larger scales. This suggests that caution should be exercised when using mathematical modeling for elucidating the specific processes that may be influencing reactive-solute transport for a given system. We also evaluate the impact of microscopic-scale mass transfer heterogeneity on field-scale transport in systems for which hydraulic conductivity is spatially variable. The results show that inclusion of locally heterogeneous mass transfer does not appear to significantly influence the mean transport behavior for systems with field-scale heterogeneity. However, it does appear to influence low-concentration tailing. For simulations of reactive transport over extended distances, models with locally heterogeneous mass transfer may 'preserve' the nonequilibrium effects associated with rate-limited mass transfer better than models incorporating locally uniform mass transfer when both pore-scale and field-scale heterogeneity coexist.

AB - Two major approaches have been used to incorporate heterogeneous ratelimited mass transfer into mathematical models for solute transport. One focuses on processes operative at the microscopic scale and associated grain-scale heterogeneity, while the other stresses the macroscopic variability of the medium and the field-scale behavior of solute transport. In this paper, we examine the conceptual framework and model formulation of these two approaches in an attempt to evaluate potential commonality. Numerical solvers are developed for both sets of governing equations, and the performance of these two models is tested for two systems, each incorporating one of two types of mass transfer mechanisms. The results show that despite differences in conceptualization and formulation, the models produce comparable behavior for smallerscale systems. However, greater deviations are observed at larger scales. This suggests that caution should be exercised when using mathematical modeling for elucidating the specific processes that may be influencing reactive-solute transport for a given system. We also evaluate the impact of microscopic-scale mass transfer heterogeneity on field-scale transport in systems for which hydraulic conductivity is spatially variable. The results show that inclusion of locally heterogeneous mass transfer does not appear to significantly influence the mean transport behavior for systems with field-scale heterogeneity. However, it does appear to influence low-concentration tailing. For simulations of reactive transport over extended distances, models with locally heterogeneous mass transfer may 'preserve' the nonequilibrium effects associated with rate-limited mass transfer better than models incorporating locally uniform mass transfer when both pore-scale and field-scale heterogeneity coexist.

UR - http://www.scopus.com/inward/record.url?scp=0033810214&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033810214&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0033810214

VL - 36

SP - 2853

EP - 2867

JO - Water Resources Research

JF - Water Resources Research

SN - 0043-1397

IS - 10

ER -